Gearing.



j H. c. WALTER.

Patented Dec. 3, 1918.

2 SHEETS-SHEET 2- I men/i03 0. War/$5563 by W I UNITED STATES PATENT OFFICE.

HENRY C. WALTER, or nnmenronr, CONNECTICUT, ASSIGNOR 'ro THE LOCOMOJBIL'E COM PANY or VIRGINIA.

To all whom it may] concern:

Be it known that I, HENRY. C. WALTER, a citizen of the United States,.and a resident of Bridgeport, county of F airfield, and State of Connecticut, have'invented an Improvement in Gearings, of which the following description, in connection with the accompanying drawings, is a specification, like characters on the drawings representing like arts. v P This invention'relates to toothed gearing, and is more especially concerned with gearing of a special type in which each tooth has portions oppositely inclined with relation to the axis of the gear as viewed from the periphery or face thereof, such as exemplified by the gearing of United States Letters Patent No.. 1,213.311, issued January 23rd, 1917, to The' Locomobile-Com- 'pany of America as my assignee.

My invention will be best understood by reference to the following specification, when taken in connection with'the accompanying drawings of one specific embodi-' ment thereof, while its-scope will be more particularly pointed out in the appended claims.

In the drawings:

Figure 1 is a plan of a portion of a bevel gear and pinion embodying my invention;

Fig. 2 is an elevation of t e same as viewed from the outer end of the pinion;

Fig. 3 is a sectional view on line 3-3 of of Fig. 1, looking toward the left; and

Fig. 4 is a layout or diagram representing the mode of laying out the tooth curve on the development of the pitch cone of the ear.

g Referring to the drawings, and to the em- 0 iment of my invention which I have selected for illustration. while my present invention is applicable to spur gears, I have herein shown for purposes of exemplification a bevel gear 5 and a pinion 6 whose pitch cones have a common apex A, while the line AB in Fig. 3 represents an element common to the rolling surfaces of the two pitch cones. In other words, the line A- represents the line of contact of two imaginary cones.

he gear 5 is provided with teeth 7 and the pinion 6 with teeth 8 whose pitch and be suitable for the nawidth of. face may be performed and the ture of the work to G ABING.

' I I I Specification of Letters Patent.

Application filed March 19,

speaking. "This radius is represented by the line CD s5 lected within certain AMERICA, OF BRIDGEPQRT, CONNECTICUT, A=CORPOBATION OF WEST 1917., Serial No. 155,635.

PatentediDec. 3, 1918.

the teeth and the' anethod employed in dethe sub]ect matter of the aforesaid patent,i'n

be noted that each tooth is-curved from end to end on an arc of a circle. and that the same radius is used for both sides of the tooth at the pitch line, or more accurately in the surface of the pitch cone.

m Fig. 4. The location of the center C from which the radius is struck' may be arbitrarily selimits. the only essential being. however, that the. point of tangency E of the arc to the radial line A-F rawn from the cone center (Fig. 4) shall be intermediate the ends of the tooththat is to say, it should lie within the face of the gear. It will be understood that when the point of tangencvis located as just described. the two portions of the teeth on opposite sides of this point exert thrusts in opposite directions. respectively, so that one counteracts the other much sense that the opposed angular tooth surfaces of a common herringbone type'of gear oppose each other. In the example selected 1n the same or illustration. the center Cfrom which the E is located somewhat'nearer the inner end of the tooth flank is found to produce of the tooth-that is to say, it is not exactly a gear still quieter in its action than midway between the ends of the tooth. that of said patent,while still preserving the The width of the face isindicatedby'theline advantages of absence of end thrust. This o H I intersecting the two arcs which repincreased quietness of action is due tothe 70 resent theouter and inner limits of thegear fact that I have eliminated that portion of face. If the teeth of the gear are cut righ the flank which resembles in a general way, hand, so to speak, the teeth of the pinion or may be likened to, common forms of will be cut left-hand; that is to say, viewing straight teeth, and thus utilize only those 10 the face of the gear and pinion as seen in portions of the curved flank as are inclined 7o Fig.1 for example, the uppermost teeth of to a substantial extent; In this way, I sethe pinion have a curve which is opposite cure the advantages .of a tooth having a slidto that of the teeth of the gear. This is reping action throughout, similar to helically resented diagrammatically in Fig 4, by laycutgears.

1 ing out a second are correspond ng to the While the recesses 9 and may be pther- 80 are drawn on theradlus CD. This second Wise suitably formed, they are herein reare for the purpose of comparison I have cessed on an arc of a circle struck from a designated CD',its center C being located center intermediate the ends of such tooth, within a circle struck on the radius AG.; and having a radius substantially less than The distance from thecenter C to the center that of the are on which the teeth faces are 86 C in Fig, 4: 1s such that the arcs struck formed. This are is represented diagramtherefrom on the radii C--D and C-D inmatically in Fig. 4 by a circle struck from tersect at a point J in the circle struck from the center L with any arbitrary radius, as the center A on the, radius AB, and for example the radius LM. It will be 2 which represents the outer circle of the gear observed that thecenter of this arc, as well 90 face. as that of the are on which the tooth is 7 It Wlll now be observed that the two arcs formed, lie in a plane intersecting the axis struck from the centers C and C have an- 7 of the gear or pinion, as the case may be.

other po1nt of intersection K, which falls Whil I have herein shown and described 0* outside of the gear face whose width isrepone specific form or embodiment of my in- 95 resented by the line H- I. As before stated, vention for illustrative purposes, and have however, the distrl wn Of he arc of the disclosed and discussed in detail the contooth within the width of the gear face is a struction and arrangement incidental to one matter of selection within certain limits alspecific application thereof. it is to be underready defined. In the present instance, the stood that the invention is limited neither to 100 point of tangency E is located somewhat the mere details or relative arrangement of nearer the inner circumference of the gear arts, nor to its specific embodiment herein face than the outer, with the result that the shown, but that extensive deviations from inward pressure of the teeth is very slightly the illustrated form or embodiment of the 4 greater than the outer pressure, the tendency invention may be made, without departing 106 therefore being to move the pinion toward from the principles thereof. the center of the gear. Although this is not Having thus described my invention, what at all necessary it has been done in the I claim and desire by Letters Patent to sepresent instance with a view to distributing cure i i the wear better on the flanks of the terminal 1. A pair of mating gears whose teeth 110 portions of the teeth. have portions oppositely inclined with rela- As thus far described, the gears selected tion to the axis as viewed from the periphfor purposes of exemplification are identical cry or face of the-gear. each of said teeth with those forming the subject matter of the having its flank provided with a recess inaf r sa d p ent termediate twooppositelv inclined portions III In accordance with my present invention, of the tooth, said recess being formed on a, the gears of said patent are modified and ,curve differing from that of said tooth flank. improved by providing each tooth 7 of the l 2. A pair of mating gears whose teeth gear with a recess 9, and by providing each have portions oppositely inclined with relatooth 8 of the pinion with a similar recess tion to the axis as viewed from theperlph- 12 10. Such recesses in each case are intermedicry or face of the gear. and each of said teeth ate two oppositely inclinedportions of the having the central portion of its flank retooth. These recesses provide clearance cessed to provide an arcuate clearance space spaces intermediate two inclined working intermediate two inclined working flank surflank surfaces of each tooth, with the result faces. 1?

that the central portion is removed or cut 3. A pair of mating gears whose teeth are away, and there remain only those two each formed on an arc of a circle struck parts of each tooth which are inclined from a center intermediate the ends of such to a substantial degree. The elimination tooth. each of said teeth having the central of this portion of the contacting surface portion of its flank recessed to provide a J clearance space intermediate two contacting ends of such tooth and of a radius substanflank surfaces. ,tially less than that of the first mentioned 4. A pair of mating gears Whose teeth circle. have portions oppositely inclined with rela- 6. A pair of mating gears whose teeth are tion to the axis as viewed from the peripheach formed on an arc of a circle struck cry or face of the gear, each of said teeth from a center intermediate the ends of such having its flank provided "with a recess tooth, each of said teeth having the central formed on an arc ofa circle struck from a portion of its flank recessed on an arc of a center intermediate the ends of such tooth circle struck from a center intermediate the and cutting the tooth flank at oppositely innds of such tooth and of a radius substanclined portions thereof. tially less than that of the first mentioned 5. A pair of mating gears whose teeth are circle, the centers of both said arcs being in I each formed on an arc of a circle struck one plane intersecting the axis of the gear. from a center intermediate the ends of such In testimony whereof I have signed my tooth, each of said teeth having the central name. to this specification. portion of its flank recessed on an arc of a circle struck from a center intermediate the HENRY C. WALTER. 

